Modelling and analysis of extreme materials for energy applications

The goal of the project is to find a suitable material that can be used at the inner wall of a nuclear fusion reactor. The material degrades due to heat, ions and neutrons. This degradation is modelled with a multiscale model.

Currently large international projects are going on to realize a power plant based on nuclear fusion (see Figure 1). Such power plants would be relatively clean sources of electricity, and would partly solve the world’s energy problem.

The nuclear fusion reactions (Figure 2) occur in a plasma (a charged gas). The high temperature plasma is contained (Figure 1) by magnetic fields. Some of the plasma will touch the wall, leading to plasma-wall interactions that can damage the wall. Especially at the divertor (Figure 1 and 3), the wall receives severe loads, consisting of neutrons, ions and heat.

Figure 2: The divertor. The upper part consists of plasma-facing material (which is black) with cooling tubes and the lower part is the structural part of the divertor.

The divertor has an important function, namely to extract the heat from the plasma, so that it can be used for the generation of electricity. One of the most critical problems that has to be solved before a commercial power plant could be realized, is the lifetime of the material in the upper part (Figure 3) of the divertor. The material should withstand the high plasma loads for a sufficient amount of time: at least a few years.

In this project we try to find a solution to obtain sufficient lifetime for the divertor, by (1) creating a model of the degradation of the material. The model will be multi-scale, and will include different processes that can each lead to damaging of the material. Understanding of the degradation mechanisms will then (2) lead the way to better choices for the divertor material and design.

Special interests in the modelling include a description of the microstructure, description of the recrystallization process and the modelling of the mechanical effects of neutron damages.